Effective leadership requires the combination of highly developed cognitive skills, a broad-base of knowledge and the prudent application of both to a given situation. In unstable and unpredictable environments, leaders are forced to be decisive, making decisions that have far-reaching consequences. However, they neither have the luxury of time nor complete information to facilitate rapid decision-making. This paper discusses how it is possible for a leader to be both prepared and ready for operating in complex environments with success through the application of Boyd's OODA loop and consequent OODA thinking.